Side opening shuntless disconnect switch



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Original application February 16, 1951,'Serial No. 211,374. Divided andthis application May 9, 1952, Serial No. 286,978

Claims. 1

This application is a divisional application of Serial No. 211,374 filedFebruary 16, 1951.

This invention relates to high voltage air switches and moreparticularly to side opening insulator stack type switches, in which themain current path is free of braided flexible conductors and thereforecalled shuntless.

Many disconnect switches have been mounted on three insulators, one tocarry the stationary contacts, one the movable contact arm assembly, andone the operating crank or assembly for the movable contact arm. Themovable contact arm was arranged so that it might rotate angularly fromthe position away from its contacting position to a position where itengages the stationary contact. The movable contact arm was alsoarranged so that after its contact carrying end entered the stationarycontact, the movable contact arm was rotated into high pressureengagement.

In most prior constructions, it was thought necessary that a currentcarrying connection be established from one terminal of the disconnectswitch directly to the contact arm, and since two separate motions werenecessary to establish contact, it was thought that a flexibleconnection permitting rotation of the movable contact in two planes wasessential to ensure that a good current carrying connection would at alltimes be made from the terminal to the movable contact arm.

When such flexible connections were properly weatherproofed andotherwise protected, they proved highly efficient, but sometimes becauseof incomplete weatherproofing or unusual weather or other operatingconditions, it happened that these flexible connections tended tocrystallize and break or corrode to failure.

Various attempts to obviate th need for the flexible connection havebeen substantially limited to construction wherein the movable contactarm was made as a bridging contact so that the terminal extending to thesource of electric current was directly connected to a stationarycontact and the terminal to the load was also directly connected to astationary contact.

Various other attempts have been made to provide for sliding contacts inplace of flexible connections at the pivot point of the contact arm. Inall of these cases, either the sliding contact was exposed to atmosphereand subjected to weathering or other corroding elements or the angle ofmovement of the contact element was such that the contact end becamecumbersome in use or size, difiicult to manufacture or inefficient incurrent carrying capacity.

2 The primary object of the present invention is to provide a toggletype of contact arm, the toggle knee pin or hinge serving as a currentcarrying contact and the toggle contact arm having a combination toggleand contact spring to supply the pressure required to make and break thetoggle as well as the contact pressure required at the toggle hingeelectrical contact.

Another object of this invention is to provide more simplified currentcarrying elements by using the combination toggle and contact spring asa current path to supplement the main current path through the toggle.The spring then serves as a resilient solid metal conductor.

Another object of this invention is to provide the toggle connectionwith a combination toggle and contact spring which may be mounted and.worked equally well either on the inside of the toggle or on theoutside.

Another object is to provide a toggle hinge contact which is enclosedand weather-sealed.

A still further object is to provide a weathersealed high pressure spotcontact type blade hinge terminal.

Another object is to make such switches easy to change from clockwise tocounterclockwise operation.

A further object of this invention is to make possible the lengtheningor shortening of the distance from toggle path to rotating insulator,making possible the adjustment of the contact surface of the toggle headcasting in jaw contacts to assure proper adjustment.

These and other objects of the invention will become apparent in thefollowing description in which:

Figure 1 is a plan view of the disconnect switch of this invention, morespecifically of a single pole side-opening shuntless type switch for 600amps.

Figure 2 is a front view of the disconnect switch of Figure 1.

Figure 3a shows a plan view of the jaw assembly of the switch of Figure1.

Figure 3b is a front view of the jaw assembly of the switch of Figure 1.

Figure 4a shows a plan view of the switch blade assembly of the switchof Figure 1.

Figure- 4b is a front view of the switch blade assembly of the switch ofFigure 1.

Figure 5 shows a plan view of a modified form of switch blade assembly.

Figure 6a shows a plan view of the blade hinge terminal assembly of theswitch of Figure 1.

Figure 6b shows a front view of the blade hinge terminal assembly of theswitch of Figure 1.

Figure 6c is a side view of the blade hinge terminal assembly of theswitch of Figure 1.

Figure 7a is a plan view of a modified switch blade assembly for a 600amp. switch with rectangular blade tube.

Figure 7b is a front view of a modified switch blade assembly for a 600amp. switch with rectangular blade tube.

Figure 8a is a plan view of a modified switch blade assembly of a 600amp. switch with rectangular blade tube and sealed internal hingecontacts.

Figure 8b is a front view of a modified switch blade assembly of a 600amp. switch with rectangular blade tube and sealed internal hingecontacts.

Figure 9a is a front view of a sealed internal hinge contact of a switchblade assembly with round blade tube.

Figure 9b is a plan view of a sealed internal hinge contact of a switchblade assembly with round blade tube.

Figure 10a is a plan view of a switch blade assembly with round bladetube with the hinge contact weatherproofed by a rubber cover.

Figure 10b is a front view of a switch blade assembly with round bladetube with the hinge contact weatherproofed by a rubber cover.

Figure 11a is a front view of the combined toggle and contact springusing two torsion type springs straddling the toggle hinge joint.

Figure 112) is a plan view of the combined toggle and contact springusing two torsion type springs straddling the toggle hinge joint.

Figure 12a is a plan view of a combined toggle and contact spring usingtwo weather-sealed helical compression springs straddling the togglehinge joint.

Figure 122) is a front view of a combined toggle and contact springusing two weather-sealed helical compression springs straddling thetoggle hinge joint.

Figure 13a is a front view of the jaw assembly of the disconnect switchof this invention, more particularly of a single pole side openingshuntless type switch for 1200 amps.

Figure 13b is a plan view of the jaw assembly of the disconnect switchof this invention, more particularly of a single pole side openingshuntless type switch for 1200 amps.

Figure 14a is a front view of the switch blade assembly of the switch ofFigure 1 using threaded toggle hinge contact pins.

Figure 14b is a plan view of the switch blade assembly of the switch ofFigure 1 using threaded toggle hinge contact pins.

Figure 15a is a front view of the blade hinge terminal assembly of theswitch of Figure 1, more paticularly for 1200 amps.

Figure 15b is a plan view of the blade hinge terminal assembly of theswitch of Figure 1, more particularly for 1200 amps.

Figure 15c is a side view of the blade hinge terminal assembly of theswitch of Figure 1, more particularly for 1200 amps.

Referring first to Figures 1, 2, 3a and 3b, the jaw assembly [6 iscomposed of three main parts, support casting I, contact tips 2 andblade stop casting 3. The support casting l is secured to the stationaryor jaw insulator [8. The two con tact tips 2 and the blade stop casting3 are secured to the support casting I in any suitable manner.

Referring then to Figures 1, 2, 4a and 4b, the complete switch blade [5is made up of the following main parts: toggle head casting 8, hingecontact pins 9a and 9b, blade end plug I0, blade tube H and the combinedtoggle and contact spring [2.

The spring I2 is secured to the blade tube II and the toggle headcasting 8 by pins B and A with cotter pins at their ends in a mannerhereinafter described. The switch blade shown in Figure 4a. has a sealedinternal toggle hinge contact; one pin 9a could be made a right-handthread and the other 9b left-hand thread to give a turnbuckle effect andcreate side pressure on the threads when the switch is closed. A rubberring seal or gasket I8 is provided to seal the internal hinge contactsand space I9 is filled with "No-ox-id or other suitable erosionexcluding or inhibiting material.

When the switch is closed as in Figure 1, the current flows from theterminal of jaw assembly |3a to the jaw contact tips 2, from the jawcontact tips 2 to the contact I! of the toggle head 8 of the bladeassembly l5, then along the toggle head of the blade 8, through pressureloaded toggle hinge contacts 911 and 91), blade end plug it, and intothe blade tube H along blade tube H and into blade hinge casting 4(Figures 6a and 6b). The blade end plug I0 is a knurled press fit intoblade tube H. The combined toggle and contact spring 12 is preferablymade of beryllium copper, a high conductivity resilient metal, and wouldthus be a high electrical conductivity spring member.

Assuming the pins B and A at the end connection of this spring member l2to be of relatively high conductivity metal, then with high pressurespot contacts 46 at the points where the spring ends Bl bear against theend connection pin A or B and with this end connection pin a press fitinto the toggle head casting 8 and blade end plug [0, respectively, thecombined toggle and contact spring [2 supplements the main toggle hingecontact 9 and serves as a parallel path through which the current canpass from the toggle head casting 8 to the blade end plug [0.

This can be seen more clearly in Figure 5, a variation of this switch.In this figure, the main current goes from the toggle head contact 2|through the toggle head 22, the main toggle hinge contact 24 into theblade tube 26. The auxiliary path of current is from the highconductivity pin 23a, through the high conductivity combination toggleand contact spring 25, here shown mounted on outside of toggle, to thehigh conductivity pin 23b. The two pins 23a and 23b form a high pressurespot contact with the toggle head casting 22 and the blade tube 26.

Referring finally to Figures 1, 2, 6a, 6b and 6c, the blade hingeterminal assembly I4 is made up of essentially four parts, blade hingecasting 4, blade clamp casting 5, pressure loaded hinge contact pin 6and terminal casting 1. When the switch is closed, the current flowsfrom the blade tube ll into the blade hinge casting ii, to the sealedpressure hinge contact pins 6, into the hinge terminal casting l and outthe terminal pad of this casting 7.

As in the case of the toggle hinge contact, one blade hinge terminalcontact pin 6a could be made right-hand thread and the other 6b lefthandthread to create a turnbuckle effect. 01 both pins 6a and 6b could bemade right-hand threads and a compression spring 52 placed between thepins Ba and 6b bearing against the ends 49 of said pins 6a and 6bproducing a longitudinal pressure on the pins so that the threads 50aand 50b of the pins 6a and 6b are in close current carrying engagementon one side in the threads 5| of the terminal casting 1. The hingecontacts are sealed by rubber ring seals 20.

Referring to the single pole switch of Figure l, the operation of theswitch from closed to open position is as follows:

Initial rotation of the rotating insulator It would collapse the toggle.The toggle is collapsed through the physical displacement of point Awith respect to points 13 and under the influence of the pressuresupplied by the combined toggle and contact spring [2.

When the toggle has been collapsed to the 55 position, or when the pointA has been displaced 55 from the line BO with point 0 taken as thepivot, the contact line of the toggle head 8 has moved longitudinally ina direction toward the rotating insulator 13. At this 55 toggleposition, the toggle head 8 will clear the jaw contact tips 2 and willpermit the entire blade assembly to be moved in the arc of opening.Pressure on toggle hinge contact pins 9a and 91) will be at its minimumvalue in this position.

Additional rotation of the rotating insulator 13 will swing the blade l5away from the jaw I 6 to any desired blade open position, giving adefinite visible break between the switch blade l5 and the switch jawI6.

During the entire opening cycle as outlined above, it is to be notedthat the hinge contacts 1 Ba and 6b at the blade hinge terminal Id arein constant engagement. The current path is not broken at any time atthe hinge terminal i4. Torque in the form of a rigid conductorconnection at the hinge terminal It prevents rotation of hinge terminal1 during the movement of the blade IS in the arc of opening or closingthe switch.

Upon closing the switch from the full open position, the followingsequence is encountered:

Efiort applied to rotating insulator [3' moves the blade l5 in the arcof closing. This blade movement is undisturbed until the toggle headcasting 8 strikes the blade stop casting 3 of the jaw assembly I6. Thecombination toggle and contact spring l2 holds the toggle head casting Bin the collapsed or position. Therefore,

when the toggle head casting 8 strikes the blade stop casting 3, it isat 55 from the center line of the blade.

Since the blade stop '3 prevents further rotational movement of thetoggle head 8, additional effort applied at the rotating insulator I3tends to close the toggle; in other words, tends to bring points A, "Band O of the toggle into alignment. While this takes place, the contactsurface of the toggle head 8 moves longitudinally and in a directiontoward the contact tips 2 of the jaw assembly 16. Also, the combinationtoggle spring 12 is subjected to increasingly greater deflection whichin turn increases the lateral loading on the toggle hinge contact pins9a and 9?). Thus, the contact pressure imparted to the toggle hingecontact pins 9a and 9b is maximum when the switch is closed.

Suflicient movement of the rotating insulator [3 will stretch out thetoggle a desired amount F until the contact surface H of the toggle head8 seat properly in the jaw contact tips 2. With the toggle in thisposition, a stop surface on the toggle head casting 8 engages a stopledge 6-8 on the blade end plug Ill thus limiting rotation of 6 thetoggle head 8 with respect to blade tube II. At this point, the switchblade I5 is in the fully closed position and the current path is asoutlined above.

By proper choice and arrangement of stop surface on toggle head 8 andstop ledge 48 of blade end plug in, the toggle action may be stoppedgeometrically at any one of three positions when the switch is closed.These positions are:

1. Before point A reaches line OB extended;

2. Just as point A reaches line OB so that points A and B and O are allon the same line; or

3. When point A has passed line 013 extended.

Under position 1) above, the combination toggle-contact spring l2 wouldtend to collapse the toggle toward the open position.

Position (2) above, with the three toggle points in line would find notendency of the spring l2 to aifect or change the relationship of thethree toggle points.

Under position (3) above, the toggle spring 12 would tend to collapsethe toggle; but in this case, in a direction away from the open toggleposition.

As mentioned above, the final portion of the switch closing operationaccomplishes a stretching out of the toggle. The combinationtogglecontact spring 12 pressure would increase as the toggle isstretched out farther and farther and would become maximum when theswitch is fully closed. This is a very desirable feature in that thecontact pressure for the toggle hinge contact pins 9 is maximum withswitch closed and becomes minimum when the switch is opened. Verydesirable too is the fact that this increased contact pressure isacquired without increasing the operating effort required at therotating insulator l3. Because, as the toggle spring 12 pressure becomesgreater when the toggle is stretched out, the torque on the toggle head8 decreases because of the rapid decrease of the effective toggle torquearm which is measured as the perpendicular distance from point 0 to theline connectign points A and B. Final contact pressure on the togglehinge contact pins 9 may be made to suit by a properly designedtoggle-contact spring [2.

Arcing horns may be used with the side break switch of Figure 1. Thestationary horn would be clamped in place on the blade stop casting 3and the movable arcing horn would be suitably clamped to the blade tube1 l. The switch shown in Figure 1 is for clockwise rotation of rotatinginsulator i 3. By turning the blade in the blade hinge casting 4 and byreversing the blade stop casting 3, the switch may be set up forcounterclockwise rotation of rotating insulator 13. When the rectangularblade tube is used as in Figure 7, the blade end plug 2! is secured in asuitable way to the rectangular blade tube 53. Instead of two contactpins as in Figure 1, only one pin 28 is used. Pin 28 is used here purelyas a means of mechanically retaining the toggle head to the blade endplug 21. The electrical contact surface is the semi-cylindrical,pressure loaded surface at the junction of the toggle head and blade endplug 21. A flexible rubber shield for contact hinge may be designed tocover the space shown in Figure '7 as either A, B, C, D, or E, F, G, H,J, K.

Using a rectangular blade tube, a sealed internal hinge contact isobtained as shown in Figure 8 where two rubber ring seals 29 seal thein- 7 ternal hinge contact while the inside space 30 is filled withNo-ox-id or other corrosion resisting material.

Similarly, if a round blade tube is used, a sealed internal hingecontact is obtained as in Figure 9 by putting two rubber ring seals 3|on the hinge contact pin 65 and by filling the internal space 3'2 withNo-ox-id.

If a round blade tube is used and the hinge is to be protected, anarrangement similar to that of Figure 10 could be used. In Figure 10, arubber shield or cover 33 is secured in a suitable way around thecontact hinge 34. A modification of the combined toggle and contactspring is shown in Figure 11 where 35 is the upper torsion type springand 35 is the lower torsion type spring. Both springs straddle thetoggle hinge joint 31. When the switch is closed, the two springs are intension.

Another modification of the combined toggle and contact spring is shownin Figure 12 where an upper 38 and lower 39 helical compression springsecured on one side to the toggle head and on the other to the bladetube straddle the toggle hinge joint 40. Here too, the two helicalcompression spring assemblies are in tension when the switch is closed.The springs 38 and 39 are enclosed in a housin 4| and sealed fromweather.

In the 1200 amp. switch, the jaw assembly in Figure 13 is of largerdimensions than that of the 600 amp. switch because of the largercurrent flow. More particularly, there are two sets of contact tips 42secured in a suitable manner to the support casting 43.

The same larger dimensions can be found in the switch blade assembly ofthe 1200 amp. switch as shown in Figure 14. The blade end plug 44 has adifferent shape from that of the 600 amp. switch but it is also aknurled press fit in the round blade tube 45. Finally, the terminalhinge assembly of the 1200 amp. switch as shown in Figure 15 also haslarger dimensions than the 600 amp. switch shown in Figure 1.

In the foregoing, I have described my invention in connection withpreferred illustrative embodiments thereof. Since many variations andmodifications of my invention will now be obvious to those skilled inthe art, I prefer to be bound not by the specific disclosure hereincontained but only by the appended claims.

I claim:

1. A disconnect switch having a movable contact arm and a complementarycontact; said movable contact arm comprising a toggle having a pair oflinks connected at a hinge; a terminal; the free end of one of saidlinks being connected to said terminal, a member connected to androtating said movable contact arm about a predetermined angle foreffecting engagement and disengagement between said contact arm and saidcomplementary contact, the free end of the other link having a contactengageable with said complementary contact; a current carrying contactat said hinge for conducting current from one of said links to the otherof said links, the connection between said free end of the firstmentioned link and said terminal comprising a rotatable current carryinghinge structure; said last mentioned hinge structure comprising athreaded member on said terminal and a complementary co-axial threadedmember on said link; means driving the threads of said members intoclose current carrying engagement.

2. A disconnect switch having a movable contact arm and a complementarycontact; said movable contact arm comprising a toggle having a pair oflinks connected at a hinge; a terminal; the free end of one of saidlinks being connected to said terminal, a member connected to androtating said movable contact arm about a predetermined angle foreffecting engagement and disengagement between said contact arm and saidcomplementary contact, the free end of the other link having a contactengageable with said complementary contact; a current carrying com tactat said hinge for conducting current from one of said links to the otherof said links, the connection between said free end of the firstmentioned link and said terminal comprising a rotatable current carryinghinge structure; said last mentioned hinge structure comprising athreaded member on said terminal and a complementary co-axial threadedmember on said link; means driving the threads of said members intoclose current carrying engagement, and a weather excluding enclosure forsaid current carrying threads.

3. A disconnect switch having a movable contact arm; a complementarycontact; a terminal; one side of said contact arm being connected tosaid terminal; the connection between the contact arm and said terminalcomprising a threaded member carried by said terminal and acomplementary co-axial threaded member on said contact arm interengagedwith the first mentioned threaded member; a member connected to androtating said movable contact arm about a predetermined angle foreffecting engagement and disengagement between said contact arm and saidcomplementary contact, means driving the threads of said members intoclose current carrying engagement.

4. A disconnect switch having a movable contact arm and a complementarycontact; a terminal; one side of said contact arm being connected tosaid terminal; said terminal comprising a threaded member and acomplementary co-axial threaded member on said contact arm: a memberconnected to and rotating said movable contact arm about a predeterminedangle for effecting engagement and disengagement between said contactarm and said complementary contact, means driving the first mentionedthreaded member in one direction and effecting a close eng'agementbetween the surfaces of the threads of said threaded members; thesurface to surface engagement of annular portions of said threadsforming a current carrying connection.

5. A disconnect switch having a movable contact arm and a complementarycontact; a terminal; one side of said contact arm being connected tosaid terminal; said terminal comprising a threaded member and acomplementary coaxial threaded member on said contact arm; a memberconnected to and rotating said movable contact arm about a predeterminedangle for effecting engagement and disengagement between said contactarm and said complementary contact, means driving the first mentionedthreaded member in one direction and effecting a close engagementbetween the surfaces of the threads of said threaded members; thesurface to surface engagement of annular portions of said threadsforming a current carrying connection, said driving means comprising acompression spring biasing said first mentioned threaded member in onedirection and effecting a close engagement between the surfaces of thethreads of said threaded members; the surface to surface engagement ofannular portions of said threads forming the current carryingconnection.

6. A disconnect switch having a movable contact arm and a complementarycontact; a terminal; one side of said contact arm being con nected tosaid terminal; said terminal comprising a threaded member and acomplementary coaxial-threaded member on said contact arm; a memberconnected to and rotating said movable contact arm about a predeterminedangle for effecting engagement and disengagement between said contactarmand said complementary contact, means driving the first mentionedthreaded member in one direction and effecting a close engagementbetween the surfaces of the threads of said threaded members the surfaceto surface engagement of annular portions of said threads forming acurrent carrying connection; the surface to surface engagement ofannular portions of the threads of said threaded member forming acurrent carrying connection; means sealing said engaged annular surfacesof said threads.

7. A disconnect switch having a movable contact arm and a complementarycontact; a terminal; one side of said contact arm being connected tosaid terminal; said terminal comprising a threaded member and acomplementary co-axial threaded member on said contact arm; a memberconnected to and rotating said movable contact arm about a predeterminedangle for effecting engagement and disengagement between said contactarm and said complementary contact, means driving the first mentionedthreaded member in one direction and effecting a close engagementbetween the surfaces of the threads of said threaded members; thesurface to surface engagement of annular portions of said threadsforming a current carrying connection, the surface to surface engagementof annular portions of the threads of said threaded member forming acurrent carrying connection, and two sealing members, one at each end ofthe first mentioned threaded member; said current carrying threads beingenclosed between said sealing members.

8. A disconnect switch having a movable contact arm, a complementarycontact, a terminal, one side of said contact arm being connected tosaid terminal, the connection between the contact arm and said terminalcomprising two threaded members carried by said terminal and acomplementary co-axial threaded member on said contact arm interengaged.with the first mentioned threaded member; a member connected to androtating said movable contact arm about a predetermined angle foreffecting engagement and disengagement between said contact arm and saidcomplementary contact, means driving the threads of said members intoclose current carrying engagement, and means sealing said currentconnection.

9. A disconnect switch having a movable contact arm, a complementarycontact, a terminal, one side of said contact arm being connected tosaid terminal, the connection between the contact arm and said terminalcomprising two threaded members carried by said terminal and acomplementary co-axial threaded member on said contact arm interengagedwith the first-mentioned threaded member, a member connected to androtating said movable contact arm about a predetermined angle foreffecting engagement and disengagement between said contact arm and saidcomplementary contact, a spring driving said complementary co-axialthreaded members in opposite directions and effecting a close engagementbetween the circuits of the threads of said threaded members; thesurface to surface engagement of annular portions of said threadsforming the said current carrying connection; means sealing said currentcarrying connection.

10. A hinge connection for a disconnect switch comprising an internallybored extension, said extension being threaded at the ends; twocomplementary co-axial threaded members interengaged with the threadedend of said extension; a spring driving the said complementary co-axialthreaded members in opposite directions and effecting a close engagementbetween the surface of the threads of said threaded members; the surfaceto surface engagement of annular portions of said threads made of a highconductive resilient metal of the beryllium copper type and forming thesaid current carrying connection; two sealing members, one on each endof said extension, sealing said engaged annular surfaces of said thread.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,9e9,'0l8 Koppitz Feb. 27, 1934 2,227,925 Cornell et a1 Jan.7, 1941 FOREIGN PATENTS Number Country Date 151,479 Switzerland Mar. 1,1932

